Automatic original circulating and feeding apparatus

ABSTRACT

An automatic original circulating and feeding apparatus apparatus comprises an original feeding base for receiving a plurality of originals thereon, which are piled up with image faces thereof turned downwardly, an original separating and feeding device for successively separating the piled up originals on the original feeding basee one by one from a lowermost original and feeding them one by one in an order separated, a reversible and speed-changeable belt conveyor device disposed in an exposure part for exposing each of the orignals fed, and a sensor disposed at a position separated by at least the largest original length from the original separating and feeding mechanism, for selectively setting a scanning copy mode or a sheet through copy mode and for controlling a position of the original for a copy mode selected.

BACKGROUND OF THE INVENTION

This invention relates to an automatic original circulating and feedingapparatus in a copying machine.

Some of the conventional copying machines is provided with an automaticoriginal circulating and feeding apparatus, i.e. what is called RADF,which, for the purpose of improving the original processing capacity ofa copying machine, permits a plurality of originals to be copied in aplurality of cycles by causing the originals to be automatically fed andrecovered cyclically.

The RADF of this operating principle is generally provided with africtional type paper separating mechanism for successively separatingone by one originals piled up on an original feeding base from thelowermost original and forwarding them one by one to the copyingmachine.

Now, the conventional RADF is considered here as applied to the copyingof double-faced originals. These double-faced originals piled up in theconsecutive order of page numbers are set on the original feeding basein such a manner that the first page will form the uppermost originalturned upwardly and the originals will be forwarded to the copyingmachine in the reverse order of page numbers. In this case, since thelast page which is copied first is turned downwardly on the originalfeeding base, it must be turned upside down before it is forwarded ontoa contact glass and set in the copying position. This is because thepenultimate page constitutes itself a downwardly turned copy surface onthe contact glass when this conveyance of the page is made on a turnfeed route. The original in this state, therefore, is turned upside downon a switchback type route so that it will be placed on the contactglass with the last page turned downwardly. This operation inevitablyrequires each original to be conveyed and set through an idle step whichhas no part at all in the actual copying machine, entailing waste oftime and impairing efficiency of the copying operation. Again when thepenultimate page is to be copied, the same original must be sent throughthe same route before it is set on the contact glass. While one originalis being copied, none of the feed routes is allowed to admit the nextoriginal. Thus, the conventional RADF necessitates a waiting time and,in this respect, operates with a slow processing rate. Particularly whenthe copying machine proper is capable of a high-speed processing, it iscompelled to be operated at a lowered speed because the RADF of such aslow processing rate cannot keep pace with the high-speed operation ofthe copying machine. As the result, the use of the RADF prevents anyeffort to improve the CPM (copies per minute; efficiency of copyingwork).

When the double-faced originals are piled up consecutively in the orderof page numbers with each of the originals turned upside down, theoriginals can be forwarded solely through a feed route to the copyingmachine. This setup, however, entails a troublesome work of causing allthe originals to set severally upside down.

Even in the case of single-faced originals, they are fed out andrecovered consecutively in the order of page numbers with theoriginal-bearing face of each original turned upwardly. Since the timeto start feeding the next original is restricted for the purpose ofpreventing two originals from passing each other on the contact glass,this arrangement also impedes the improvement of CPM.

SUMMARY OF THE INVENTION

In the light of the true state of affairs of the prior art describedabove, this invention aims to provide an automatic original circulatingand feeding apparatus which the originals are set as turned downwardlyand fed out consecutively in the order of page numbers, enables theoriginal feeding work to be carried out at a speed matched to the speedof the continuous operation of the copying machine proper, therebypermitting the improvement of the CPM and, at the same time, enablingthe feeding work to be optimized to suit either single-faced originalsor double-faced originals.

The present invention provides an automatic original circulating andfeeding apparatus comprising an original feeding base for receiving aplurality of originals thereon, which are piled up with image facesthereof turned downwardly, an original separating and feeding mechanismfor successively separating the piled up originals on the originalfeeding base one by one from a lowermost original and feeding them oneby one in a order separated, a reversible and speed-changeable beltconveyor mechanism disposed in an exposure part for exposing each ofsaid originals fed, and a sensor disposed at a position separated by atleast the largest original length from the original separating andfeeding mechanism for selectively setting a scanning copy mode forforwarding a given original to a predetermined position above theexposure part, stopping the original at the predetermined position andsetting an optical exposure system into a scanning motion for exposureor a sheet through copy mode for stopping the optical exposure systemrelative to the exposure part and forwarding the original by the beltconveyor mechanism for exposure and for controlling a position of theoriginal for a copy mode selected.

Since the automatic original circulating and feeding apparatus accordingto this invention is constructed as described above, piled up originalsarranged consecutively in the order of page numbers and set on theoriginal feeding base with the image faces turned downwardly can beforwarded continuously in the order of page numbers and copied at aspeed matched to the speed of the continuous copying speed of thecopying machine proper without being affected by the resistance exertedin the original separating and feeding mechanism. In the copying ofsingle-faced originals, for example, the selection between the scanningcopy mode keeping the original stopped and the optical exposure systemin operation and the sheet through copy mode keeping the opticalexposure system stopped and the original conveying system in operationand the selection between the RADF mode and the ADF mode both can bemade freely and the copying machine as a whole is enabled to enjoy animproved CPM.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view illustrating one embodiment of this invention.

FIG. 2 is a schematic side view illustrating a drive transmission systemin the embodiment.

FIG. 3 is an explanatory diagram illustrating a route for passage ofsingle-faced originals in the embodiment during the course of copying.

FIG. 4 is an explanatory diagram illustrating a route for passage ofdouble-faced originals of the embodiment during the course of copying.

FIG. 5 is a side view illustrating another embodiment of this invention.

FIG. 6 is an explanatory diagram illustrating a route for passage ofsingle-faced originals in the aforementioned another embodiment duringthe course of copying.

FIG. 7 is an explanatory diagram illustrating a route for passage ofdouble-faced originals in the aforementioned another embodiment duringthe course of copying.

FIG. 8 is a side view illustrating a modification of the aforementionedanother embodiment.

FIG. 9 is an explanatory diagram illustrating a route for passage ofdouble-faced originals in the conventional copying machine during thecourse of copying.

FIG. 10 is an explanatory diagram illustrating a route for passage ofsingle-faced originals in the conventional copying machine during thecourse of copying.

FIG. 11 is an explanatory diagram illustrating a looped route forpassage of originals in the conventional copying machine.

DESCRIPTION OF THE PREFERRED EMBODIMENT

This invention is not limited to the embodiments to be specificallycited herein. It may be practised as modified or altered or altered innumerous ways without departing from the spirit of the invention.

First, the conventional countertype will be described in detail belowfor clarifying the distinction of the present invention.

When double-faced originals 1 are to be copied as illustrated in FIG. 9,these double-faced originals 1 are consecutively set in the order ofpage numbers as indicated by P1˜P6 with the first page P1 lying in theuppermost position as turned upwardly and they are fed out in thereverse order of page numbers, with the sixth page P6 to be copiedfirst. Here, the sixth page P6 to be copied first is turned downwardlyon the original feeding base, it must be turned upside down so as to beforwarded to and readied for copying on a contact glass 3 which isprovided with a conveyor belt 2. Otherwise, the fifth page P5constitutes ifself a downwardly turned copy face on the contact glass 3when the sheet bearing the sixth page P6 is conveyed along a turn feedroute as indicated by ○1 . Thus, the original 1 as held in the statementioned above is turned upside down by means of a switch-back typefeed route as indicated by ○2 , ○3 , and ○4 so that the sixth page P6will be forwarded to and set on the contact glass 3 as turneddownwardly. This means that the original is forwarded and set by beingpassed through an idle step which has no part at all in the actualcopying work, entailing waste of time and impairing the efficiency ofcopying work. When the fifth page P5 is to be subsequently copied, thesame original bearing the fifth original must be similarly passedthrough the feed route as indicated by ○2 , ○3 , and ○4 before it is seton the contact glass 3. Further, the feed route as indicated by ○1 , ○2, ○3 , and ○4 , while one original 1 is being copied, is not allowed toadmit the next original. Thus, this setup necessitates a waiting timeand, in this respect, operates at a low processing rate. Particularlywhen the copying machine proper is capable of a high-speed processing,it is compelled to be operated at a lowered speed because the RADF ofsuch a slow processing rate cannot keep pace with the high-speedoperation of the copying machine. As the result, the use of the RADFprevents any effort to improve the CPM (copies per minute; efficiency ofcopying work).

When the double-faced originals 1 are piled up in the descending orderof P2, P1, P4, P3, P6, and P5 with respect to the diagram of FIG. 9, theoriginals may be processed only through the feed route of ○1 . Thissetup, however, entails a disadvantage that all the originals 1 must beset as arranged in the aforementioned order.

Even in the case of single-faced originals 4, they are set consecutivelyin the order of page numbers with the image faces thereof turnedupwardly as illustrated in FIG. 10, then forwarded through the feedroute of ○1 in the reverse order of page numbers, and discharged andrecovered through the feed route of ○4 via a discharge roller 5. Thetime to start feeding the next original is restricted for the purpose ofpreventing two originals from passing each other on the contact glass 3.Thus, this setup enjoys no improvement of CPM.

Now, the present invention will be described more specifically belowwith reference to preferred embodiments illustrated in the accompanyingdrawings. First, as illustrated in FIG. 1 through FIG. 4, an RADF 12 isdisposed in such a manner as to cover a contact glass 11 which isdisposed on the upper side of a copying machine proper 10. The RADF 12is provided with a belt conveyor mechanism 17 comprising a conveyor belt16 supported between a driving roller 13 and a driven roller 14 andfurnished with a plurality of pressure rollers 15. At the upstreamposition to the right of this belt conveyor mechanism 17, an originalfeeding base 18 and an original separating and feeding mechanism 19 aredisposed in the direction of the aforementioned contact glass 11 side.The original feeding base 18 is disposed as inclined toward the contactglass 11 side and adapted to permit a plurality of originals 20 piled upconsecutively in the order of page numbers, with the image faces thereofturned downwardly. This original feeding base 18 is provided with amovable side fence 21 adapted to permit positioning of the originals inthe direction of width. The original separating and feeding mechanism 19is interposed between the original feeding base 18 and the contact glass11 and is provided with a feed route 22 which continues to the loadingsurface of the original feeding base 18 and communicates with thecontact glass 11. Below the original feeding base 18, a semicircularpinching roll 23 made of sponge of coefficient of frictional μ=1.0, anda Milar film 24 adapted to press an original 20 against the pinchingroll 23 are disposed. There are futher disposed a separating roller 25made of murubber, for example, and a separating blade 26 held in pressedcontact with the separating roller 25 and made of urethane havingcoefficient of friction μ, of not less than 1.2. Here, anelectromagnetic clutch (not shown) is connected to the pinching roll 23and the separating roller 25. While the feeding of originals is started,it is driven at a rate of one rotation per original. Then it is drivenby the motion of the original 20. On the contact glass 11 side, a pairof pullout rollers 27, 28 are disposed.

An original sensor 29 is interposed between the pinching roll 23 and theseparating roller 25. Another original sensor 30 is located immediatelybefore the contact glass 11.

A reverse feeding mechanism 31 is disposed on the downstream side to theleft of the belt conveyor mechanism 17. This reverse feeding mechanism31 is formed mainly of a turn roller 32 of a large diameter. A roller 33and a turn guide 34 disposed continguously with the turn roller 32jointly form a reverse route 35 around the periphery of the turn roller32. The reverse route 35 is provided at the outlet thereof with a switchgate 36 serving to switch a conveyor route as a first switch gate deviceis rotatably disposed. Further, the turn roller 32 is provided on thefollowing roller 14 side thereof with a guide claw 37. Around the innerside (conveyor belt 16 side) of the turn roller 32, a reverse feedingroute 38 is formed as directed toward the aforementioned contact glass11 side. An original sensor 39 is located immediately before the feedroller 33

A discharging device 41 is also located which is provided with adischarge route 40 substantially horizontally interconnecting the outletof the reverse feeding mechanism 31 provided with the switch gate 36 andthe upper part of the original feeding base 18. The discharge route 40is formed of a guide part 43 made of a RADF cover 43 as a device coverand a guide member 44. A plurality of pair conveyor rollers 45, 46, 47are disposed as opposed to the discharge route 40. A discharge roller 48is disposed near the original feeding base 18.

A switchback reverse conveyor mechanism 49 as a discharge feedingmechanism adapted to effect selective passage of a document is disposedhalfway along the length of the discharge route 40 in the dischargingdevice 41. This switchback reverse conveyor mechanism 49 comprises aturn roller 50 having a diameter equal to the diameter of theaforementioned turn roller 32, a triangular guide member 53 disposed onthe paper discharge side from the turn roller 50 and adapted to form aturn route 51 and a straight discharge route 52, a switch claw 54 assecond switch gate serving to switch between the turn route 51 and thestraight discharge route 52, feed rollers 55, 56 held in contact withthe turn roller 50 with the turn route 51, and a switchback route 57utilizing the upper side of the RADF cover 42.

At a prescribed position of the discharge route 40, at the inlet to theturn roller 50, and on the turn roller 50, original sensors 58, 59, and60 are respectively disposed. Further, the guide member 53 is providedat the leading end side thereof with a paired conveyor rollers 61. Adischarge sensor 62 is disposed on the nearer side of the dischargeroller 48.

The present embodiment is allowed to select either the scanning copymode for keeping the original 20 at the prescribed position P₂ on thecontact glass 11 and setting an optical exposure system 64 such as of alamp 63 into a copying motion from the home position HP or the sheetthrough copy mode for keeping the optical exposure system 64 such as thelamp 63 directly below the pressure roller 15 on the driven roller 14side and forwarding the original 20 at a prescribed speed by theconveyor belt 16 to effect desired copying. On part of the opticalexposure system 64, a resist sensor 65 is mounted as opposed to thecontact glass 11. It is employed for the control of the position forstopping the original during the scanning copy mode or for aligning theleading end of the original 20 in motion with the leading end of thetransfer paper on the copying machine proper 10 side during the sheetthrough copy mode.

Then, the construction of the drive transmission system in the RADF 12of the present embodiment will be described below with reference to FIG.2. A first motor 70 for actuating the original separating and feedingmechanism 19 is provided. With a motor cogwheel 71 on the axis of thefirst motor 70, two stepped cogwheels 72, 73 disposed on pullout roller(upper) shaft 28a are meshed through the medium of an intermediatecogwheel 74. A cogwheel 75 on the separating roller shaft 25a is meshedwith the motor cogwheel 71 through the medium of the aforementionedintermediate cogwheel 74. A cogwheel 78 on the pinching roll shaft 23ais meshed with the cogwheel 71 through the medium of a cogwheel 76coaxial with the cogwheel 75 and an intermediate cogwheel 77. Thepullout roller 28 is set at a high pressure enough to forward theoriginal 20 in spite of the pressure of separation exerted on theseparating part.

There is also provided a second motor 79 serving to actuate the drivingroller 13 for the conveyor belt 16. This second motor 79 is of the DCservo type. A motor cogwheel 80 disposed on the axis of the second motor79 is meshed with a cogwheel 81 on the aforementioned driving rollershaft 13a through the medium of intermediate cogwheels 82, 83 and acogwheel 84. The driving roller 13 is reversibly driven by the secondmotor 79 with the speed thereof freely controlled.

There is further provided a third motor 85 for driving part of thereverse feeding mechanism 31 such as turn roller 32 and the dischargedevice 41. A pulley 88 is fitted on the axis of a cogwheel 87 which ismeshed with a motor 86 on the axis of this third motor 85. Between thispulley 88 and a pulley 89 on the turn roller shaft 31a and pulleys 90,91, and 92 disposed on the conveyor roller (lower) shafts 45a, 46a, and47a, a timing belt 94 is passed through the medium of a pressure guideroller 93. Again in this case, the speed at which the turn roller 32,etc. are driven is varied by changing the revolution number of the thirdmotor 85.

There is provided a fourth motor 95 which serves for the switchbackreverse feeding mechanism 49 and the discharge roller 48. A pulley 98 isfixed on the shaft of a cogwheel 97 which is rotated by a cogwheel 96 onthe shaft of the fourth motor 95. A belt 100 is passed between thepulley 98 and a pulley 99 on the turn roller shaft 50a. Between thispulley 98 and pulleys 101, 102 on the roller shaft 61a and the dischargeroller shaft 48a, a belt 103 is passed. The turn roller 50 and thedischarge roller 48 are allowed to vary their speeds by the change ofthe revolution number of the fourth motor 95.

The distance between the turn roller 32 of the reverse feeding mechanism31 and the turn roller 50 of the switchback reverse feeding mechanism 49is greater than the maximum length of original (the longitudinal size ofA3, for example). The distance between the sheet through position P₃ andthe pullout rollers 27, 28 is also greater than the maximum length ofthe original.

Now, the feeding operation performed on the original 20 set on theoriginal feeding base 18 in the construction described above will beexplained below. The originals 20 are set as piled up consecutively inthe order of page numbers, with the image faces turned downwardly. Asthe copy button on the copying machine proper 10 side is turned on, amotor 167 serving for a patition plate 166 which partitions a pile oforiginals 20 is turned on to set the partition plate 66 on the originals20. Then, the first motor 70 is set operating and the pinching roll 23and the separating roller 25 are actuated to separate and feed out thelowermost original 20 toward the pullout rollers 27, 28. It is thenforwarded on the contact glass 11 by the pullout rollers 27, 28 and theconveyor belt 16. As regards speeds of operation, the speed of theseparating roller 25 is fixed at about 500 mm/s and the speeds of thepullout rollers 27, 28 and the conveyor belt 16 are fixed approximatelyin the range of 750 to 800 mm/s.

These operations of separating and feeding of originals are carried outin common based on varying operation modes. Now, the operations ofvarying modes will be described. First, the sheet through copy mode(RADF mode) will be explained. This mode is selected where a finisher ora doggy tail is used for aftertreatment of a copy paper and thecondition in which the relation of the original to the copy is 1:1 isrepeated. In this mode, the optical exposure system 64 is kept stoppeddirectly below the pressure roller 15 on the driven roller 14 side.While the apparatus is in this state, since the original 20 is forwardedas pressed down against the surface of the contact glass 11 by thepressure roller 15, it is not suffered to rise from the contact glassand consequently is prevented from producing an uneven image due tojittering, for example. When the resist sensor 65 detects the arrival ata prescribed point of the leading end of the original 20 which has beenbrought up on the contact glass 11 by the conveyor belt 16, the speed ofthe travel of the conveyor belt 16 is changed from a high to a low leveland, at the same time, the motion of a transfer paper within the copyingmachine proper 10 is synchronized with the new speed of the conveyorbelt, as a step preparatory to sheet through copying. In this case, thetrailing end of the original 20 completes departure from the pulloutrollers 27, 28 by the time the leading end thereof reaches the positionP₃ for sheet through exposure. Since the position P₃ for the sheetthrought exposure is set on the left end side of the conveyor belt 16,the original being forwarded on the conveyor belt 16 for the sheetthrough copying can be advanced and exposed to light at a fixed speed ina state perfectly free from the influence of such load as pressure ofseparation exerted by the separating roller 25 and the pullout rollers27, 28. Again in this respect, the freedom of copied image from suchadverse phenomena as jittering is ensured all the more.

In the meantime, the leading end of the original 20 being advanced onthe conveyor belt 16 as simultaneously exposed to light continues itstravel toward the reverse route 35 and the discharge route 40 from abovethe contact glass 11. At this time, the turn roller 32 or the conveyorrollers 45, 46, and 47 are driven at a speed equal to or slightly lowerthan the speed of the conveyor belt 16. As the result, the original 20is not drawn by the turn roller 32 or any other roller but is advancedon the contact glass 11 at the fixed speed governed by the conveyor belt16.

When the advance of the original 20 in the manner described aboveproceeds and the leading end of the original reaches the neighborhood ofthe turn roller 50, since the switch claw 54 keeps the turn route 51side open during the present mode, the original 20 advances around theturn roller 50 and continues its travel toward the switchback dischargeroute 57 utilizing the upper surface of the RADF cover 42. At this time,the trailing end of the original completes its departure from theexposure position. As the sensor 60 detects the arrival at a prescribedpoint of the trailing end of the original, the conveyance on the roller50 is stopped and the turn roller 50 is driven backwardly. As theresult, the original 20 whose leading end has been advancing toward theswitchback discharge route 57 is now caused to make a switchback changeof its direction of travel and consequently forwarded toward thedischarge roller 46 side by the turn roller 50 with the trailing end atthe lead. Since these rolelrs 50, 46 are rotating at high speed in thiswhile, the original 20 is released by the discharge roller 48 onto theoriginal feeding table 18.

Now, the feeding of a subsequent original 20 will be considered. When aprescribed time elapses after the complete departure of the trailing endof the preceding original 20 advanced on the conveyor belt 16 for thepurpose of the sheet through exposure is detected by the sensor 30, thefirst motor 70 is set rotating and the pinching roll 23 and theseparating roller 25 are caused to start separating the lowermost one ofthe piled originals 20. When the sensor 30 detects the arrival of theleading end of the subsequent original 20, the pullout rollers 27,28 areswitched to a state of low-speed driving to advance the subsequentoriginal toward the contact glass 11 as kept at a fixed distance fromthe trailing end of the preceding original on the contact glass 11.

In the manner described above, the plurality of originals 20 piled up onthe original feeding base 18 are consecutively forwarded in the order oftheir page numbers toward the contact glass 11 form the lowermost sheetupwardly, subjected to the copying by the sheet through exposure, andrecovered successively on the original feeding base 18 again in theorder of their page numbers. When the last of the piled originals is fedout, this fact is detected by the gravimetric rotary fall of thepartition plate 66. When the last original is recovered, it is set bythe motor 67 at the top of the pile. Thus, the pile of originals isready for the next cycle of feeding. The operation described above isrepeated until a desired number of copies has been produced.

During the course of the sheet through copy mode, the original 20 isexposed to light as simultaneously advanced at a fixed speed by theconveyor belt 16. In this case, when the condition of the fixed-speedconveyance of the conveyor belt 16 is rendered variable in a pluralityof steps, the copying machine is allowed to produce copies of imagesmangified by varying ratios.

The scanning copy mode (ADF mode) in which the original is fixed inplace and the optical exposure system 64 is caused to produce a scanningmotion is selected where a sorter is employed for the aftertreatment ofa copied paper and the first of the plurality of originals 20 isrepeatedly processed for production of a desired number of copies beforethe second original is subjected to the same processing instead ofcausing the plurality of originals to be consecutively passed one by onethrough the copying unit. In this mode, the original 20 separated fromthe pile is advanced at a high speed on the contact glass 11 by theconveyor belt 16. When the arrival of the leading end of the original isdetected by the resist sensor 65, an encoder in the second motor 79issues a pulse signal to stop the motion of the conveyor belt and theoriginal is stopped at a fixed position. After the original hasundergone scanning exposure (of cycles required for production of adesired number of copies) of the optical exposure system 64. Then, theconveyor belt 16 is set again into motion, enabling the original to bepassed through the reverse feeding mechanism 31 and advanced at a highspeed through the discharge route 40. During the present mode, since theoriginal 20 is no longer required to be recovered for further feeding onthe original feeding base 18, it is passed through the turn route 51around the turn roller 50 and released onto the switchback dischargeroute 57. Thus, the upper side of the RADF cover 42 is utilized as atray. In this case, the RADF cover 42 may be provided on the surfacethereof with a stack cover 68 made of translucent acryl resin asindicated by an imaginary line in FIG. 1, for example, to provideprotection for the originals 20 released onto the switchback releaseroute 57.

The originals 20 are partly of single-faced type and partly ofdouble-faced type. Now, the treatment proper to each of the types willbe described below. In the case of a plurality of single-facedoriginals, they are set on the original feeding base 18 as piled upconsecutively in the order of their page numbers, with the first page P1on the lowermost position and the image faces of the originalsinvariably turned downwardly as shown in FIG. 3. In this state, theoriginals 20 are successively fed out one by one toward the contactglass 11 from the lowermost original and subjected to the sheet throughcopying or the scanning copying. The original is advanced through theturn roller 32 and the discharge route 40. In the sheet through copymode, the original is advanced around the turn roller 50, switched backby the switchback discharge route 57, and released by the dischargeroller 48 for recovery. In the scanning copy mode, the original isreleased onto the switchback discharge route 57. In response to themotion of the original 20 described above, the time for starting thefeed of a copying paper 111 to a sensitive member 110 is synchronizedwithin the copying machine proper 10 to effect control of paper feeding,for example, with the result that an image on the sensitive member 110is trnasferred onto the transfer paper 111. Then, the copy paper 111which has undergone the transfer of image is passed through a dischargeroller 112, forwarded into a reversing part 113, and released asreversed onto a tray (not shown). Consequently, the transfer papers 111are piled up as arranged consecutively in the order of page numbers withthe image faces thereof turned downwardly.

Incidentally, in the case of single-faced originals, the discharge ofthe originals through the switchback reverse mechanism 49 brings aboutthe following merit. When a plain RADF is considered as shown in FIG. 2,an original feeding base is installed on a conveyor belt 2 and originals4 are successively forwarded through a looped circular conveyor route 6and recovered. While the originals 4 are cyclically conveyed in a numberof times, they are gradually disposed to be easily curled under theinfluence of the shape of the circular conveyor route 6 and the pressureof the turn roller 7, for example. As the result, they extrude from theoriginal feeding base and frequently cause such adverse phenomena asjam. In accordance with the present embodiment, as readily noted fromthe flow of originals 20 shown in FIG. 3, since the originals aredischarged after they are turned by the turn roller 50 in the directionopposite the direction in which they have been turned by the turn roller32, the curl once imparted is corrected. Particularly since these turnrollers 32, 50 are formed in substantially equal diameters, the effectof correction of the curl is conspicuous and the effeciency of recoveryof originals in the original feeding base 18 is high and the possibilityof inducing the phenomenon of jam is diminished.

Now, the treatment of originals 20 and transfer papers 111 to beinvolved when a plurality of double-faced originals are given to becopies will be described below with reference to FIG. 4.

Similarly in this case, the originals 20 are set on the original feedingbase 18 as piled up consecutively in the order of their page numbersfrom the lowermost original. The separation and feeding of theindividual originals to the contact glass 11 is carried out in entirelythe same manner as in the case of single-faced originals. Since theoriginals are of the double-faced type in this case, the first originalplaced on the contact glass 11 is subjected to the copying in such amanner that the first page P1 will constitute the lower sied and thesecond page P2 the upper side respectively. After the original hasundergone exposure to light, it is forwarded toward the reverse route35. In this case, since the second page p2 remains yet to be copied, theswitch claw 36 is switched into a state of closing the discharge route40 side. As the result, the original 20 is forwarded around the turnroller 32 and into the reverse route 38 this time. The conveyor belt 16is also driven backwardly. As the result, the original 20 is set on thecontact glass 11 in the opposite direction. In this state, the secondpage P2 of the original is turned downwardly and is ready for exposureto light. In response to the conveyance of the original 20 in the mannerdescribed above, the transfer sheet 111 has a copy formed on one sidethereof by the sensitive member 110, then reversed by the reverse part114, and released temporarily into an intermediate tray 115. Then, fromthe intermediate tray 115, the transfer sheet 111 now bearing a copiedimage on one side thereof is forwarded through a paper feed roll 116 anda resist roller 117 as synchronized with the motion of the original 20again to the sensitive member 110, to complete a double-faced copy.After the production of copies on both sides thereof, the transfer paper111 is forwarded through the discharge roller 112 and released directlyinto the tray. In the meantime, the original 20 which has had both sidesthereof exposed to light is advanced toward the reverse route 35. Thistime, since the switch claw 36 has been switched to a new route, theoriginal is advanced through the discharge route 40. Then, since theswitch claw 54 of the turn roller 50 is now in a state inhibiting theadvance of the original toward the switchback discharge route 57, theoriginal 20 is caused to advance straight through the straight route 52and then released by the discharge roller 48 onto the original feedingbase 18. As the result, the double-faced originals are recovered in aset state. When the originals are released onto the switchback dischargeroute 57, they are piled up in an incorrect order.

As noted from the comparison of FIG. 3 and FIG. 4, the route forconveyance of the single-faced originals is different from that of thedouble-faced originals. Since the route paper for either of the types oforiginals can be selected by means of the switch claws 36, 54, theoriginals are not required to be passed through any useless route. Inthe case of the double-faced originals, the sheet through copy modecannot be selected because the operation includes a step for returningthe originals 20 in the opposite direction on the contact glass 11.

In any event, the present embodiment provides a sequential page feedingRADF 12 which is capable of sheet through copying and, therefore,enables the copying intervals to be shortened and the CPM to be improvedby continuously feeding the originals 20 for copying. Since theconstructions is capable of effecting not merely the sheet throughcopying but also the scanning copy mode which is common for ADF, itcontributes to diversification of the mode of copying. No matter whichcopy mode may be selected, the originals can be conveyed at a fixedspeed on the conveyor belt 16 in a state free from the influences ofpressure of separation because the position of the resist sensor 65 forcontrolling the conveyance of originals 20 is separated from theoriginal separating and feeding part by a distance greater than themaximum original length. During the through copy mode, therefore, thecopied images enjoy high quality because of the freedom from the adversephenomena such as jittering and the accuracy of alignment of the leadingend of original is enhanced. During the scanning copy mode, the accuracyof the stop of original on the contact glass 11 can be improved by thesame token. Further in the case of double-faced originals, they can beconveyed through the shorted possible route without entailing any idlefeeding. Further, the load required for the conveyance through thedischarge system can be lessened since the distance between the turnrollers 32, 50 is greater than the maximum original length. Moreover,since the upper side of the RADF cover 42 can be utilized as aswitchback discharge route 57 or a discharge tray, an original which isnot desired to be passed repeatedly through the conveyor route may bereleased onto the upper side of the RADF cover and consequentlyprevented from sustaining unwanted harm.

Then, other embodiments of the present invention will be described belowwith reference to the diagrams of FIGS. 5 to 7. From the overall pointof view, they are similar to the RADF 12 of the preceding embodiment,excepting ideas for compaction are reflected. Like parts are denoted bylike reference numerals. In one of such other embodiments, an originaldischarge tray 121 is disposed to the left of the contact glass 11. Aswitchback reverse conveyor mechanism 122 which constitutes a reverseand discharge mechanism together with said reverse feeding mechanism andsaid discharging device is disposed to the left of the upper side of thereverse roller 32, namely in the direction opposite that of thedischarge route 40. This switchback reverse conveyor mechanism 122comprises a switchback route 123 formed by opening the RADF cover 42 inthe horizontal direction, a reversing roller 124 disposed at the outlet,and an original sensor 125 positioned directly before the reversingroller 124. There is provided a switch claw 126 serving the purpose ofswitching the direction of advance of the original 20 having conveyed tothe turn route 35 around the aforementioned turn roller 32 between thedischarge route 40 side and the aforementioned switchback route 123side. This switch claw 126 can be utilized also for the purpose ofguiding the original 20 when it is desired to be forwarded through theaforementioned switchback route 123 and returned toward the dischargeroute 40. This switch claw 126 is further provided with a Mylar valve127 adapted to prevent backflow.

The aforementioned discharge route 40, as compared with the countertypein the preceding embodiment, is formed linearly as far as the dischargeroller 48 part and is additionally furnished with paired conveyorrollers 128, 129.

In still another of the embodiments, one motor is adapted to produceboth normal and reverse drivings similarly to the turn roller 32 as faras the reversing roller 124 or the paired conveyor rollers 128, 129. Thedischarge roller 48 is driven independently by one motor. In thisarrangement, the speed of the discharge roller can be freely changed forthe purpose of improving the efficiency of recovering and stackingoriginals 20 on the original feeding base 18. This stacking property isfurther enhanced by impartation of nerve to the originals 20.

In the construction described above, the scanning copy mode in which theoptical exposure system 64 is caused to produce a scanning motion forexposure and the sheet through copy mode in which the optical exposuresystem 64 is kept in a fixed state and the original 20 is exposed tolight as simultaneously conveyed can be carried out in entirely the samemanner as in the preceding embodiment.

When single-faced originals are given to be copied, the conveyor routefor the original shown in FIG. 6 is selected. When the original 20 whichhas been exposed to light as simultaneously conveyed onto the contactglass 11 enters the turn route 35 on the turn roller 32 side, since theswitch claw 126 has been turned to keep the switchback route 123 sideopen, the original 20 is advanced although this route and then forwardedby the reversing roller 124 toward the exterior of the RADF cover 42. Inthis case, the original which has emerged from the RADF cover 42 hangsdown and is held up by the discharge tray 121 disposed below. When theoriginal sensor 125 detects the arrival of the rear end of the original20, the reversing roller 124 is temporarily stopped and then drivenbackwardly. At the same time, the switch claw 126 is turned to open thedischarge route 40 side. As the result, the original 20 which hasadvanced through the switchback route 123 is caused by the reversingroller 124 to change its direction of travel in the pattern of aswitchback and then forwarded through the discharge route 40. It is thenreleased by the discharge roller 48 onto the original feeding base 18 byway of recovery. Consequently, the originals 20 are recovered in thesame state as originally set.

Where single-faced originals are to be processed in the scanning copymode, the originals 20 which have undergone exposure to light may bedirectly released onto the discharge tray 121 by menas of the switchbackroute 123 and the reversing roller 124. This operation permits areduction in the route for passage of the original and proves to beadvantageous for originals 20 of the nature not desired to be exposed tothe friction of passage.

Where double-faced originals 20 are given to be copied, they areforwarded through a route as illustrated in FIG. 7. When the front pageof the double-faced original 20 is exposed to light on the contact glass11, the original is advanced toward the turn route 35. In this case,since the switch claws 126 and 36 have been turned to open the reverseroute 38 side around the turn roller 32, the original 20 is advancedthrough this reverse route 38. At this time, the double-faced original20 is in a state turned upside down. Also, the conveyor belt 16 is setrevolving in the opposite direction. As the result, the original 20 isset on the contact glass 11 with the reverse side thereof turneddownwardly and in that state exposed to light. After this exposure, theswitch claws 126, 36 are turned to open the ordinary discharge route 40side. Thus, the original is forwarded around the turn roller 32 andthrough the discharge route 40 and released by the discharge roller 48onto the original feeding base 18. In this case, too, the originals arerecovered in the same state as initially set.

In yet another embodiment, the RADF cover 42 is formed as an integralcomponent. It is optional that it may be split into two parts, i.e. aRADF cover 42a extending from the neighborhood of the turn roller 32through the neighborhood of the conveyor roller 129 and a RADF cover 42bformed on the original separating and feeding part as illustrated inFIG. 8, with only the RADF cover 42a side adapted to be freely shut andopened.

What is claimed is:
 1. An automatic original circulating and feedingapparatus comprising an original feeding base for receiving a pluralityof originals thereon, which are piled up with image faces thereof turneddownwardly, an original separating and feeding mechanism forsuccessively separating said piled-up originals on said original feedingbase one by one from a lowermost original and feeding them one by one isan order separated, a reversible and speed-changeable belt conveyormechanism disposed in an exposure part for exposing each of saidoriginals fed, and a sensor disposed at a position separated by at leastthe largest original length from said original separating and feedingmechanism, for selectively setting a scanning copy mode for forwarding agiven original to a predetermined position above said exposure part,stopping said original at said predetermined position, and setting anoptical exposure system into a scanning motion for exposure of a sheetthrough copy mode for stopping said optical exposure system relative tosaid exposure part and forwarding said original by the belt conveyormechanism for exposure and for controlling a position of the originalfor a copy mode selected.
 2. An automatic original circulating andfeeding apparatus as claimed in claim 1, in which said reversible andspeed-changeable belt conveyor mechanism comprises a belt conveyor, areverse feeding mechanism discharged at a downstream of said beltconveyor in a direction in which said exposed originals are fed, forreversing said exposed originals fed from said belt conveyor, adischarging device disposed in the neighborhood of said reverse feedingmechanism for feeding said exposed and reversed originals fed from saidreverse feeding mechansim, and a discharge feeding mechanism disposed insaid discharging device for selectively discharging said exposed andreversed originals from said discharging device to an outside of saidapparatus through an opening provided on a cover disposed on saiddischarging device or to said original feeding base.
 3. An automaticoriginal circulating and feeding apparatus as claimed in claim 1, inwhich said reversible and speedchangeable belt conveyor mechanismcomprises a belt conveyor, a reverse and discharge mechanism disposed ata downstream of said belt conveyor in a direction in which said exposedoriginals are fed, for reversing said exposed originals fed from saidbelt conveyor and for selectively discharging said exposed and reversedoriginals to an outside of said apparatus through an opening provided onsidewall of a cover disposed on said reverse and discharge mechanism orto said original feeding base.
 4. An automatic original circulating andfeeding apparatus as claimed in claim 2 or 3, in which said cover issplit into two parts.